JPH06237901A - Eyeground camera - Google Patents

Abstract

PURPOSE:To simplify an alignment work before photographing. CONSTITUTION:An objective lens 1, fore-eye part observation optical system 2 to be saved from an optical path 01 at the time of photographing, porous mirror 3, jump-up mirror 6 and film 7 are arranged on the optical path 01 in front of an eye E to be checked, and a half mirror 17 and a visible light source 19 to be turned on and to become a fixed target at the time of eyeground alignment are provided on an optical path 03 opposite to the jump-up mirror 6. An infrared television camera 21 is arranged oppositely to the half mirror 17, and the output of the infrared television camera 21 is connected to a television monitor 22. Concerning the fore-eye part observation optical system 2, a lens 23, half mirror 24 and lens 25 are arranged on the optical path 01, and a visible light source 27 to be turned on at the time of fore-eye part observation is provided in the reflecting direction of the half mirror 27 and used as a fixed target. The visible light sources 19 and 27 are conjugably arranged and at the time of alignment, the alignment is facilitated since the glance of an object to be photographed is fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fundus camera used in an ophthalmology clinic or the like.

[0002]

[Prior art]

(1) In a conventional fundus camera, a fixation target is generally provided to determine an observation and imaging part of the fundus of the eye to be inspected. The form of this fixation target is one that is provided flexibly outside the device, one that is fixed at a position almost conjugate to the fundus of the eye to be examined, or one that is movable in a plane perpendicular to the optical axis. , Various.

There is also known a fundus camera such as a non-mydriasis fundus camera which uses infrared rays to perform alignment on a television monitor. With this type of fundus camera, the anterior segment observation optical system is inserted into a part of the fundus camera optical system during alignment, that is, during anterior segment observation, and an anterior segment image is formed at a position optically conjugate with the fundus image position. However, it is common to perform alignment using the same TV camera as the fundus observation TV camera.

(2) Conventionally, when fundus imaging is performed, a movable point light source is provided outside the housing, and the point light source is moved while fixing the subject's gaze and the direction of the line of sight is changed. By making the target site enter the visual field of the fundus camera by, or by making the subject fixate the visual target which is provided inside the housing and optically projected at an arbitrary position through the objective lens, It is usual to guide the target site into the field of view for imaging.

[0005]

[Problems to be Solved by the Invention]

(A) However, in the fundus camera described in (1), the optotype is used when observing and photographing an actual predetermined part of the fundus, and is not used when aligning the eye to be inspected. Further, also in the non-mydriasis fundus camera described above, when the anterior segment observation optical system is inserted into a part of the fundus camera optical system, the position of the fixation target at the time of fundus observation and photographing is conjugate with the fundus position of the eye to be examined. It will not be seen by the subject as it does not. For this reason, there is a drawback that the subject does not have a line-of-sight target at the time of alignment of the eye to be inspected and the alignment operation becomes difficult.

(B) In the fundus camera of the type in which the point light source is provided outside the housing described in (2) above, there is a drawback that the moving range of the point light source is narrow and the image-capable area is limited. Further, in a fundus camera that optically projects a fixation target through an objective lens, it is inconvenient because it is necessary to adjust the position of the fixation target for each eye.

A first object of the present invention is to solve the above-mentioned drawback (a) and to provide a fundus camera in which the line-of-sight direction is stable even when observing the anterior segment of the eye and the alignment operation is easy.

A second object of the present invention is to solve the above-mentioned drawback (b) and to provide a fundus camera which is easy to perform a photographing operation and which can arbitrarily set a photographing region of the fundus.

[0009]

A first fundus camera according to the present invention for achieving the above object comprises an illumination optical system having an invisible light illuminating means for observing a fundus of an eye to be examined, and a fundus. In a fundus camera having a photographing optical system for photographing, and an observation optical system in which a part of the photographing optical system is common to the photographing optical system and an observer observes the fundus through a visible conversion means, the observation is performed on the optical path of the photographing optical system. An insertable / removable auxiliary optical system including a fixation target projection member including an auxiliary lens and a first fixation target is provided behind the objective lens facing the optometry, and the auxiliary lens is inserted when the auxiliary optical system is inserted. By the pupil image of the eye to be inspected is formed at the position of the fundus image when not passing through the auxiliary lens,
It is characterized in that the first fixation target is arranged so as to be substantially conjugate with the fundus of the eye to be examined through the fixation target projection member and the objective lens.

The second fundus camera is provided with a first fixation target which is projected on the eye to be inspected through an objective lens and whose projection position is arbitrarily variable, and a second fixation target which is fixed at a predetermined position. , A switching means capable of arbitrarily switching the first and second fixation targets.

[0011]

In the first fundus camera having the above structure, the auxiliary optical system is inserted in the optical path of the photographing optical system during alignment. Since the first fixation target is substantially conjugate with the fundus of the eye to be inspected, it is visually recognized by the subject and serves as a fixation target. Since the pupil image position is equal to the fundus image position when the auxiliary lens does not pass through the auxiliary lens, the observation optical system captures the pupil image.

Further, the second fundus camera selectively projects the first fixation target or the second fixation target on the eye to be inspected by the switching means according to the imaged region for fundus imaging.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments. FIG. 1 is a configuration diagram of a non-mydriasis fundus camera according to the first embodiment. On the optical path O1 in front of the eye E to be examined, there is an objective lens 1, an anterior ocular segment observation optical system 2 which can be inserted into and removed from the optical path O1 and is inserted into the optical path O1 during anterior ocular segment observation, and a central aperture. A perforated mirror 3, a focusing lens 4 movable in the direction of the optical path O1, a taking lens 5, and a flip-up mirror 6 that can be flipped up at the time of shooting are sequentially arranged, leading to a film 7 used at the time of shooting.

On the optical path 02 in the reflection direction of the perforated mirror 3, relay lenses 8a and 8b, a ring slit 9 having an annular opening, a mirror 10, a condenser lens 11, a xenon tube and the like are arranged from the perforated mirror 3 side. Shooting light source 1
2, a condenser lens 13, an infrared filter 14 that transmits infrared light, and an illumination light source 15 composed of a halogen lamp or the like are sequentially provided to form a photographing and observation illumination system. The field lens 16, the half mirror 17, the lens 18, and the visible light source 1 are provided on the optical path 03 in the reflection direction of the flip-up mirror 6.
9 is provided. A television lens 20 and an infrared television camera 21 are provided in the reflection direction of the half mirror 17, and the output of the television camera 21 is connected to a television monitor 22.

In the anterior ocular segment observation optical system 2, a lens 23, a half mirror 24, and a lens 25 are sequentially provided from the eye E side, and a lens 26, a half mirror 24, and a lens 26 are arranged in the reflecting direction of the half mirror 24.
A visible light source 2 whose line-of-sight direction is optically coincident with that of the visible light source 19.
7 is provided, and the anterior ocular segment observation optical system 2
Is inserted into the optical path O1 when observing the anterior segment of the eye and forms an image of the anterior segment on the infrared television camera 21.

An infrared light source 28 for illuminating the anterior eye part of the eye E to be inspected from above is provided above the front part of the objective lens 1 and is turned on when observing the anterior eye part. Further, during observation of the anterior segment, the anterior segment of the eye E, the image plane F near the lens 25, the image plane F ′ near the field lens 16 and the focal plane of the infrared television camera 21 are in a conjugate arrangement. The visible light sources 27 and 19 and the fundus of the eye E to be inspected are arranged in a substantially conjugate manner. Furthermore, when observing the fundus, the fundus of the eye to be examined and the visible light source 1
9 is configured to have a substantially conjugate relationship.

As a preparation for fundus imaging of the eye E to be examined, first, alignment with the fundus camera optical system is performed. The subject is seated in front of the objective lens 1 so that the subject's eye E faces and the visible light source 27, which is visible in front of the visual field, is fixed.
The anterior segment of the subject's eye E illuminated by the infrared light source 28
The objective lens 1, the lens 23 of the anterior ocular segment observing optical system 2, the half mirror 24, and the lens 25 form an aerial image on the image plane F near the lens 25, which is near the independent focus of the objective lens 1, and a perforated mirror. 3, focusing lens 4,
An image is formed again on the image plane F ′ in the vicinity of the field lens 16 via the taking lens 5 and the flip-up mirror 6. The anterior segment image is then formed on the image pickup surface F ″ of the infrared television camera 21 by the half mirror 17 and the television lens 20 and output as an image 22a on the television monitor 22. The visible light source 27 is the fundus of the eye E to be examined. Since it is a conjugate arrangement, it is clearly observed by the subject, the line-of-sight direction is stable, and alignment can be easily performed.

When the alignment with respect to the eye E to be inspected is completed, the anterior segment observation optical system 2 is retracted from the optical path O1 and fundus imaging is performed. When the illumination light source 15 is turned on, the luminous flux from the illumination light source 15 passes through the optical path 02 and is reflected by the perforated mirror 3 to illuminate the fundus of the eye E to be inspected. The fundus reflected light forms an image on the imaging surface F ″ of the infrared television camera 21 via the optical path O1 and the optical path 03, and the fundus image is output on the TV monitor 22. In this state, precise fundus alignment is performed. However, the point of gaze of the subject at that time is the visible light source 19 provided at a position substantially conjugate with the fundus of the eye E to be examined behind the half mirror 17. The visible light source 19 is clearly visible, Since the subject can gaze at the visible light source 19, the eye gaze direction does not become indefinite, and fundus alignment can be performed easily. The visible light source 19 and the visible light source 27 are in the same eye gaze direction for the eye E to be inspected. Therefore, the line-of-sight direction does not change when the anterior segment observation optical system 2 is inserted or removed.

FIG. 2 is an explanatory diagram of a screen on the television monitor 22 during fundus alignment. TV monitor 22
A fundus image 22b is displayed above. The examiner performs alignment while observing the television monitor 22, and when the alignment is matched, the focusing lens 4 is moved by a driving mechanism (not shown) while observing the fundus image 22b to perform a focusing operation and press the photographing button. Then, the flip-up mirror 6 is flipped up, the photographing light source 12 emits light, the luminous flux illuminates the fundus of the eye E through the optical path 02 and the optical path O1, and the fundus reflected light is transmitted through the optical path O1 to the film. The fundus image will be recorded on 7.

FIG. 3 is a block diagram of the anterior segment observation optical system 2'in the second embodiment. The same members as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. This anterior ocular segment observation optical system 2'is replaceable with the anterior ocular segment observation optical system 2 in FIG.
1, a lens 32, and a lens 33 are sequentially arranged along the optical path O1, and a visible light source 34 is provided in the reflecting direction of the half mirror 31. Here, the visible light source 34 is arranged so as to be conjugate with the fundus of the eye E to be inspected with respect to the objective lens 1, and is turned on at the time of alignment to be watched by the subject. Even in this situation,
Similar to the first embodiment described above, the line-of-sight direction of the examiner is always fixed, so alignment becomes easy.

4 and 5 are partial block diagrams of the third embodiment. In the third embodiment, as shown in FIG. 4, a lens 36 and a visible light source 37 are provided above the half mirror 31, and the optical axes of the visible light source 34 and the visible light source 37 coincide with each other. Further, as shown in FIG. 5, a visible light source 38 is provided on the opposite side of the television lens 20 with respect to the half mirror 17, and the optical axes of the television lens 20 and the visible light source 38 are aligned with each other.

In the first and second embodiments described above, the visible light source 19 and the visible light source 2 projected on the fundus of the eye E to be inspected.
It was unknown where the image 7 was projected onto the eye E to be examined. With such a configuration, the images of the visible light source 37 and the visible light source 38 are formed on the infrared television camera 21. Then, the fixation position of the subject can be confirmed as a dummy of the visible light source 19 and the visible light source 27. In addition,
Although one visible light source 27 and 19 and one visible light source 34 and 19 are provided, respectively, a plurality of visible light sources may be provided to light corresponding lights. Also, the eye E
A set of visible light sources having the same line-of-sight direction as viewed from the above can be made movable in a plane perpendicular to the optical axis.

FIG. 6 is a block diagram of the fundus camera according to the fourth embodiment. On the optical path 04 in front of the eye E, an objective lens 41, a perforated mirror 42 having a central opening 42a, a taking lens 43 movable in the optical path 04 direction, a flip-up mirror 44 that can be flipped up outside the optical path 04, a shutter 45, Film 4
6 are arranged in sequence. On the optical path 05 in the reflection direction of the perforated mirror 42, the relay lens 47 and the annular opening 4 are provided.
Ring slit 48 having 8a, condenser lens 4
9, an oscillating mirror 50 that is flipped up to the outside of the optical path 05, and a photographing light source 51 are sequentially arranged. Further, an infrared transmission filter 52 that transmits only infrared light in the reflection direction of the oscillating mirror 50, and an illumination light source 53. Are provided to form a fundus illuminating optical system.

On the optical path 06 in the reflection direction of the flip-up mirror 44, the first half mirror 54 arranged so as to be orthogonal to the optical path 06, the reflectance is set to be larger than the transmittance, and the optical path 06 is formed.
The second half mirror 55, the condenser lens 56, the mirror 57, and the movable reflecting mirror 58 that can be retracted outside the optical path 06 are sequentially arranged in such a manner that they are obliquely arranged, and the position can be adjusted to the front, rear, left, and right by the lever 59. Fixing target LED60
Has reached. Further, a fixation target LED 61, which is a fixation target, is provided in the reflection direction of the movable reflection mirror 58, a taking lens 62 and a television camera 63 are provided in the reflection direction of the second half mirror 55, and a television camera 63 is further provided. The output of is connected to the television monitor 64. It should be noted that the photographing light source 51, the first half mirror 54, the ring slit 48, and the perforated mirror 42 are arranged to be conjugate with each other, and the fundus Ef and the film 46 are arranged to be conjugate with respect to the photographing optical system.

When photographing the fundus, first, the illumination light source 53
Is turned on, and the fundus illuminating light converted into an infrared light flux by the infrared transmitting filter 52 is reflected by the perforated mirror 42 through the optical path 05 and reaches the fundus Ef of the eye E to be examined. The fundus reflected light is reflected by the flip-up mirror 44 via the optical path 04,
The image is once formed on the first half mirror 54, then passes through the second half mirror 55 and the taking lens 62, and then the television camera 6
An image is formed on the image pickup surface of No. 3. The examiner performs alignment using the fundus image projected on the television monitor 64. When the alignment is matched, the fixation target LED 60 and the fixation target LED 61 are turned on.

As shown in FIG. 6, when the movable reflection mirror 58 is inserted in the optical path 06, the light flux of the fixation target LED 60 is blocked by the movable reflection mirror 58, so that the subject's fixation target LED 61 is blocked. Only visible. Part of the light flux from the fixation target LED 61 is the first half mirror 5
The second half mirror 5 is reflected by 4 in the return direction.
5. The image is formed on the image pickup surface of the television camera 63 through the photographing lens 62, and is displayed on the television monitor 64 as a visual target image 61a overlapping the fundus image. It is possible to confirm whether the visual target image 61a is visually recognized at the position.

Let the examinee fixate the fixation target LED 61,
The examiner operates a shooting button (not shown). When the swing mirror 50 and the flip-up mirror 44 are flipped up and the swing mirror 50 and the flip-up mirror 44 retreat to the position indicated by the broken line, the photographic light source 51 emits light, and the shutter 45 is opened and the film 46 is placed on the film 46. The fundus image is taken at.

The fixation target LED 61 is particularly effective when it is used in imaging in which a desired imaging region is predetermined, for example, in a group medical examination in which a large number of subjects are imaged. The LED 60 is effective when a subject having a disease on the fundus or the like wants to image the fundus at a specific position. At this time, the fixation target LED 60 is presented to the subject, and the line of sight is guided by moving the fixation target LED 60 using the lever 59 to introduce the desired fundus position into the imaging visual field.

Further, in the above-described fourth embodiment, the movable reflecting mirror 58 is used to switch the mirror to be the fixation target, but a half mirror is provided instead of the movable reflecting mirror 58, and it is not shown. The LED may be dimmed or turned off.

[0030]

As described above, in the first fundus camera, the light source which is the fixation target is turned on even when observing the anterior segment of the eye, so that the examinee can see the line of sight even when observing the anterior segment of the eye. Since the direction can be kept constant and the position of the eye to be inspected is stabilized, the alignment operation becomes easy.

Further, since the second fundus camera selects the fixation target according to the application, the handling of the device is simplified and facilitated.

[Brief description of drawings]

FIG. 1 is an optical layout diagram in a first embodiment.

FIG. 2 is an explanatory diagram of a television monitor display example.

FIG. 3 is an optical layout diagram of an anterior ocular segment observation optical system in a second example.

FIG. 4 is an optical layout diagram of an anterior segment observation optical system in a third example.

FIG. 5 is an optical layout diagram of a fixation target for observation and photography in a third embodiment.

FIG. 6 is a configuration diagram of a fourth embodiment.

[Explanation of symbols]

 2 Anterior ocular segment observation optical system 12, 51 Imaging light source 15, 53 Illumination light source 19, 27, 34, 37, 38 Visible light source 21, 63 TV camera 22, 64 TV monitor 58 Movable reflection mirror 60, 61 Fixation target LED

Claims (3)

[Claims] 1. An illumination optical system having an invisible light illuminating means for observing the fundus of an eye to be examined, a photographing optical system for photographing the fundus, and a part of the photographing optical system shared with the photographing optical system so that an observer can see the fundus. In a fundus camera having an observation optical system for observing through a conversion means, a fixation including an auxiliary lens and a first fixation target on the optical path of the photographing optical system and behind the objective lens facing the eye to be examined. A removable auxiliary optical system including a target projection member is provided, and when the auxiliary optical system is inserted, the pupil image of the subject's eye is formed at the position of the fundus image when the auxiliary lens does not pass through the auxiliary lens. The fundus camera, wherein the first fixation target is arranged substantially optically conjugate with the fundus of the eye to be inspected through the fixation target projection member and the objective lens. 2. An optical path to the fundus of the eye to be inspected, which is outside the optical paths of the illumination optical system and the photographing optical system and within the optical path of the observation optical system or the optical path branched from the observation optical system. The fundus according to claim 1, wherein a second fixation target is provided at a conjugate position, and both the second fixation target and the first fixation target are conjugated with substantially the same site on the fundus of the eye to be examined. camera. 3. A first fixation target which is projected onto an eye to be inspected through an objective lens and whose projection position is arbitrarily variable, and a second fixation target which is fixed at a predetermined position. Two
The fundus camera is provided with a switching means capable of arbitrarily switching the fixation target.